1. Field of the Invention
The present invention relates generally to the field of home networking, and more particularly, to Universal Plug and Play (UPnP) enabled telephony devices.
2. Description of the Related Art
UPnP telephony service allows a user access to telephony services using home devices. This access provides the user with the flexibility to access telephony services at home using different kinds of devices. The UPnP is a set of computer network protocols promulgated by the UPnP forum. The goals of UPnP telephony are to allow home devices to connect seamlessly and to simplify implementation of networks in the home and corporate environments through, for example, data sharing, communications, and entertainment. The UPnP achieves these goals by defining and publishing UPnP device control protocols built upon open, Internet-based communication standards.
The UPnP architecture allows peer-to-peer networking of Personal Computers (PCs), networked appliances, and wireless devices. The UPnP architecture is a distributed, open architecture based on established standards such as Transmission Control Protocol or Internet Protocol (TCP/IP), User Datagram Protocol (UDP), Hypertext Transfer Protocol (HTTP) and Extensible Markup Language (XML).
The UPnP architecture supports zero-configuration networking. An UPnP compatible device from any vendor can dynamically join a network, obtain an IP address, announce its name, convey its capabilities upon request, and learn about the presence and capabilities of other devices. Dynamic Host Configuration Protocol (DHCP) and Domain Name System (DNS) servers are optional and are only used if they are available on the network. The UPnP compatible device can leave the network automatically without leaving any unwanted state information.
The UPnP telephony services also provide discovery, control and event mechanisms. The discovery mechanism is enabled using Simple Service Discovery Protocol (SSDP) protocol. All of the control messages will be in the form of XML and will follow General Event Notification Architecture (GENA) protocol. Thus, the UPnP dynamically determines the availability and unavailability of the devices “on the fly” to the other devices in the network.
The UPnP defines a new telephony services for expanding the user experience in the home to access telephony services including, for example, a messaging service, a presence services, and call handling (one of packet switching or circuit switching call).
The UPnP telephony defines the messaging services and call management service, which allows the user to access the messaging service by, for example, sending the message using devices that do not have the messaging capability and initiating the media calls. The UPnP telephony messaging service uses the basic UPnP architecture to define the messaging services and defines the actions and state variable to access the messaging services.
Analogous to UPnP Device Architecture (DA), the UPnP telephony services define the following three kinds of devices:
A (TS) Telephony Server that provides messaging, and presence related services to user. The TS also provides a call management service.
A Telephony Control Point (TCP) that is the same as a Control Point (CP). The TCP initiates the actions provided by the TS.
A Telephony Client (TC) device for media related handling, and for acting as the input and output of the device.
Current messaging services allow users to send messages, for example, messages using Short Message Service (SMS), Multimedia Message Service (MMS), Chat Instant Messaging (Chat IM) and Electronic mail (Email). The messaging services also allow the users to group the messages into one session. The message service defines the actions to create an IM session and also allows a user to modify the existing session. However, there exist no mechanism in UPnP technology for storing information for the completed session or to access the stored session history. There is also no mechanism to retrieve the messages from the session history in UPnP telephony services.